 /* RESET & BASE STYLES */
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: Arial, sans-serif;
      background: #f5f5f5;
      color: #333;
      line-height: 1.6;
    }
    header, footer {
      text-align: center;
      background: #fff;
      padding: 15px;
    }
    .container {
      max-width: 1000px;
      margin: 20px auto;
      background: #fff;
      padding: 20px 30px;
      border-radius: 8px;
      box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    }
    /* TABS */
    .tabs {
      display: flex;
      border-bottom: 2px solid #007BFF;
      margin-bottom: 20px;
    }
    .tabs button {
      flex: 1;
      padding: 10px;
      background: none;
      border: none;
      border-bottom: 4px solid transparent;
      cursor: pointer;
      font-size: 1rem;
      color: #007BFF;
      transition: all 0.3s;
    }
    .tabs button.active {
      border-bottom-color: #007BFF;
      font-weight: bold;
    }
    /* TAB CONTENT */
    .tabcontent {
      display: none;
    }
    .tabcontent.active {
      display: block;
    }
    /* SECTIONS */
    section {
      margin-bottom: 20px;
    }
    section p, section ul {
      margin-bottom: 10px;
    }
    section ul li {
      margin-left: 20px;
      list-style: disc;
    }
    /* CALCULATOR & FORMS */
    .calc {
      margin: 15px 0;
      text-align: center;
    }
    .calc label {
      display: inline-block;
      width: 180px;
      font-weight: bold;
    }
    .calc input, .calc select, .calc textarea {
      padding: 5px;
      width: 100px;
      margin-right: 10px;
    }
    .btn {
      padding: 7px 15px;
      background: #007BFF;
      color: #fff;
      border: none;
      border-radius: 4px;
      cursor: pointer;
      margin-top: 10px;
      transition: background 0.3s;
    }
    .btn:hover {
      background: #0056b3;
    }
    .result {
      margin-top: 10px;
      padding: 10px;
      background: #e9f2f9;
      border: 1px solid #ccc;
      border-radius: 4px;
      text-align: center;
    }
    /* CANVAS */
    canvas {
      display: block;
      margin: 20px auto;
      background: #fff;
      border: 1px solid #ddd;
    }
    /* FOOTER */
    footer {
      text-align: center;
      padding: 15px;
      background: #fff;
      margin-top: 20px;
      box-shadow: 0 -2px 4px rgba(0,0,0,0.1);
    }
